Great Britain's decision to ban Michael Savage because of his "extreme views" marks a dark day in the history of free speech. The shame should be particularly severe in a nation that gave birth to John Stuart Mill, the 19th century political philosopher whose writings so strongly advanced the cause of open dialogue. Mill argued in his pivotal essay "On Liberty" that intolerance to hear opposing views amounts to an assertion that the politically correct view is infallible. Doubting that any human view could be without error, Mill fought hard to convince readers of the importance of encouraging the expression...